1. Field of the Invention
The present invention relates to a Plasma Display Panel (PDP), and more particularly, to a PDP that facilitates an initial discharge to reduce a sustain voltage and to enhance luminous efficiency.
2. Description of the Related Art
When voltage is applied across two electrodes arranged in a sealed space filled with gas within a PDP, a glow discharge occurs, creating ultra violet rays which excite phosphor layers that are formed in a predetermined pattern, thereby creating an image.
PDPs can be categorized into a Direct Current (DC) type, an Alternating Current (AC) type, and a hybrid type, depending on how they are driven. Depending on the electrode structure, PDPs can also be categorized into PDPs that have two electrodes for performing a discharge operation, and PDPs that have three electrodes. In a DC type PDP, an auxiliary electrode is added to induce an additional discharge. In an AC type PDP, an address electrode is added to increase the address speed by separating a select discharge and a sustain discharge.
In addition, depending on the arrangement of the discharge electrodes, PDPs can be categorized into an opposed discharge type and a surface discharge type. In an opposed discharge type PDP, two sustain electrodes are located on a front substrate and rear substrate, respectively, thereby forming a discharge perpendicular to the panel. In a surface discharge type, two sustain electrodes are located on the same substrate, thereby forming a discharge parallel to the surface of the substrate.
A PDP includes a plurality of address electrodes having a predetermined width and height, the plurality of address electrodes being formed on a rear substrate positioned in a lower portion of the PDP. A rear dielectric layer covers the address electrodes.
Barrier ribs are formed on the rear dielectric layer to partition discharge spaces and to prevent cross-talk from occurring between adjacent discharge spaces. The discharge spaces are filled with a gas and a phosphor layer is formed on the inner side of the barrier ribs.
A front substrate is formed above the rear substrate to face the rear substrate. A pair of sustain electrodes, which include a common electrode and a scan electrode, are arranged under the front substrate. A bus electrode for applying a voltage is formed under each sustain electrode. A front dielectric layer covers the sustain electrodes and the bus electrodes, and a protective layer is further arranged under the front dielectric layer.
In the PDP having the above-described structure, the sustain electrode is formed of a transparent Indium Tin Oxide (ITO) film. Since the ITO film can cause a voltage drop due to poor conductivity, the sustain electrodes are connected to the bus electrodes. The bus electrodes are formed of metal that has a good conductivity.
A black stripe is additionally provided in an interfacial region between the discharge spaces to improve contrast to significantly affect the PDP. A PDP disclosed in Japanese Laid-Open Patent Publication No. 2003-31134 has such a black stripe.
However, since the black stripe is arranged in the interfacial region between the discharge spaces, the bus electrodes are arranged in a discharge region corresponding to the discharge spaces. Consequently, the bus electrodes, formed of an opaque metal, can reduce an aperture ratio of the PDP and block some of the visible light emitted from the discharge spaces, thereby reducing the luminance of the PDP.
To solve these problems, the PDP can be designed such that the bus electrode is placed in a non-discharge region, e.g., on the barrier rib. Thus, the aperture ratio of the PDP can be improved so as not to block visible light and reduce luminance.
However, if the bus electrode is formed on the barrier rib, the width of the sustain electrode increases so that an electric field formed in the discharge space is not sufficiently reinforced and concentrated. Thus, the luminous efficiency of the PDP is reduced.